Field of the Disclosure
The present disclosure relates generally to processing devices and, more particularly, for controlling access to a bus in a processing device.
Description of the Related Art
The advanced microcontroller bus architecture (AMBA) is an open standard, on-chip interconnect specification for the connection and management of functional blocks in processing devices such as a system-on-a-chip (SOC). For example, an AMBA-compliant interface may be used to connect various components of an SOC to a request bus in the SOC. Access to the request bus is controlled by a valid/ready protocol. A first component may assert a “valid” signal to the interface to indicate that data or control information (such as an address for a read request, an address for a write request, or data for a write request) is available for transfer on a channel of the request bus to a second component. The request bus may assert a “ready” signal to the interface to indicate that the request bus is ready to accept the data or control information. Once the valid signal from the component and the ready signal from the request bus are asserted concurrently, the data or control information is transferred from the first component to the second component over the request bus.
The SOC may also include a response bus for providing responses to the requests transmitted over the request bus such as the data produced by a read request or a confirmation of a successful write request. The response bus may assert a valid signal to indicate that the information is available for transfer on a channel of the response bus and the component may assert a ready signal to indicate that it is ready to accept the information. Once the valid signal and the ready signal are asserted concurrently, the information may be transferred to the component on the response bus.